The invention relates to an oxygen generator, preferably for welding, cutting and brazing operations, consisting of a gas-tight container and a cartridge holder insertable therein to accommodate combustible cartridges which yield oxygen in the burning state. Such a device can also be referred to as a "reactor".
In the state of the art is an oxygen generator of the above-described kind, in which the gas-tight container envelops the cartridge holder without any appreciable clearance. The cartridge holder is charged with at least one commercially available, oxygen-yielding cartridge which is provided on its one end with an igniting composition which can be ignited on the striking surface of a matchbox. The cartridge holder has at its extremity outside of the container a filter for pulverulent by-products of the combustion process, as well as a chamber to accommodate a drying agent which absorbs the water vapor released upon combustion. The chamber for the drying agent leads to a connection for a hose leading to the burner for the welding, cutting and brazing operations. Such oxygen generators are combined with a bottle containing a combustible gas such as propane or butane, which is equipped with a regulating valve leading to an additional hose which is also connected to the burner. A set of such equipment is sold principally for hobby work.
In the known apparatus, the oxygen released flows within the container through the filter and the drying agent and to the burner nozzle without appreciable pressure. Regulation of the flow of oxygen by devices on then apparatus is not possible. The consumption of oxygen is determined exclusively by the burning characteristics of the cartridges, which for this purpose are offered in a variety of types. It is possible to stop the liberation of the oxygen only by removing the cartridge holder from the container and removing the burning portion of the cartridge, for example by cutting it off. The unburned remainder of the cartridge can still be used if it is re-ignited, but this is made inconvenient by the fact that there is no longer an igniting composition on the remainder of the cartridge. As a rule, therefore, the cartridge is allowed to burn to the end, so that if the work is finished before it is completely consumed, the result is a considerable waste of cartridges. Control of the flame is possible only by varying the adjustment of the valve on the propane or butane bottle.
In the known apparatus, the gas-tight container becomes hot due to its closeness to the cartridge holder and the burning cartridge, so that a heat-resistant surface protection of the container becomes necessary, by means, for example, of an expensive electroplating process. Nevertheless, discoloration of the surface-protective coating or the blistering of the coating material cannot always be prevented. On account of the high temperature in the container, the released oxygen furthermore passes through the filter and the drying material in a very hot state, entraining moisture and heat. An excessive amount of moisture, which is absorbed by the cartridge if improperly stored, for example, is unable to condense due to the high gas temperatures, and is carried into the burner. Consequently the burner flame tends occasionally to become extinguished, and this is a nuisance. The heat content of the oxygen also appreciably shortens the life of the hose. The burner nozzles of the known apparatus are of special design on account of the low gas pressure, and they have to be adapted to each particular size of cartridge and cartridge characteristic on account of the lack of control of the oxygen flow. Consequently there are a number of obstacles to the use of the known apparatus for industrial purposes, in factories and on construction sites, for example.
On construction sites, therefore, the large and heavy high-pressure oxygen bottles having internal pressure of up to 200 atmospheres are used, although they are expensive to obtain and difficult to transport.
It is consequently impractical to carry them up ladders and scaffolds.